1. Field of the Invention
The present invention relates to an authentication apparatus and an authentication method which are suitably applied to, e.g., biometrics.
2. Description of the Related Art
There is known a vein authentication apparatus that uses vein of a finger as a target of biometrics. The vein authentication apparatus generates vein pattern information from a vein image obtained as an image pickup result of veins in a finger and collates the pattern information with pattern information previously stored in a storage section.
When a value representing the collation result is not less than a limiting value (hereinafter, referred to also as “threshold”) for identifying a person to be authenticated as a registrant, the vein authentication apparatus determines the person to be authenticated as the registrant (determines authentication success), while when a value representing the collation result is less than a threshold, the vein authentication apparatus determines the person to be authenticated as an unregistered person (determines authentication failure).
As a generation method of the pattern information, there is proposed a technique that applies smoothing processing and edge extraction processing to the vein image and converts the veins in the resultant image into a pattern of lines having a constant width (refer to, e.g., Jpn. Pat. Appln. Laid-Open Publication No. 2007-11989).
In this generation method, it is possible to correctly convert the shape of the veins into a pattern image by highlighting the veins in the image through preprocessing for the smoothing processing and edge extraction processing, thereby decreasing a false rejection rate (FRR) and a false acceptance rate (FAR). The FRR is the probability that a registrant is erroneously rejected, and the FAR is a probability that an invalid person is erroneously accepted.